The invention relates to tree spades and, more specifically, to a mechanism for mounting the individual blades of a tree spade that is adjustable to correct and maintain the desired alignment of the individual blades.
The use of tree spades for removing, transporting, and transplanting growing sizeable trees is well known. The tree spades most typically employ a plurality of upright towers supported on a ring structure which can be separated and opened to encircle a tree. The towers each support a blade which are moved upwardly and downwardly on the towers for extraction and insertion into the earth surrounding the tree. Upon insertion of the blades, any intervening roots of the tree are severed and a substantially conical shaped mass of earth is extracted together with the tree.
For efficient operation, the blades must be appropriately aligned so that they meet at a common vertex and along adjoining sides when fully extended into the earth. Not only is it difficult in the original fabrication of the tree spade to position the towers consistently and precisely so that the individual blades are all aligned, but ordinary use and wear of the tree spade will result eventually in some misalignment. In existing tree spades, it has been necessary either to cut apart and reweld portions of blade mounting brackets or align the towers by means of adjustment bolts or the like to correct such misalignments. With the present invention, alignment is simply and quickly achieved by pivotal movement of one or more eccentric clamps used in the mounting of the individual blades to the towers.